ABSTRACT
The study and measurement of intelligence has always had a political dimension, and this is particularly evident in the debate concerning the relative importance of environmental and inherited factors in determining intelligence and measured intelligence quotient (IQ). The opposing argument was that the tests themselves were culturally biased towards the better off, and that measured IQ was predominately determined by environmental factors such as early home background and schooling. When identical twins develop in different environments, the correlation between their IQ scores is lower than that for identical twins reared together, and a similar difference appears when fraternal twins are reared apart. Data from twin and adoption studies must be treated with caution because many studies suffered from methodological problems. Environmental enrichment refers to the process of providing as stimulating an environment as possible in order that a child’s intellect may develop toward the upper bound of their reaction range.
